A battery separator is a component that divides, or “separates”, the positive electrode from the negative electrode within a battery cell. A battery separator has two primary functions. First, a battery separator must keep the positive electrode physically apart from the negative electrode in order to prevent any electronic current passing between the two electrodes. Second, a battery separator must permit an ionic current between the positive and negative electrodes with the least possible resistance. A battery separator can be made out of many different materials, but these two opposing functions have been best met by a battery separator being made of a porous nonconductor.
An important parameter for describing a battery is the achievable number of cycles, or the cycle life of the battery. The cycle life indicates how often a battery can be charged and discharged repeatedly before a lower limit of the capacity is reached, or a failure. Batteries with a cycle life include all secondary batteries, or batteries that are capable of being recharged several times. There are many secondary batteries, including, but not limited to, lead-acid batteries. For economical and ecological reasons, batteries with a high cycle life are preferred.
Many batteries have a low cycle life, or fail, due to deterioration of the positive electrode conductor. The positive electrode conductor, usually in the form of a grid in a lead-acid battery, deteriorates from corrosion during the electrochemical process. The positive electrode conductor corrodes faster than the negative electrode conductor because of the greater effects of the electrochemical process on the positive electrode. The more current flowing through the positive electrode conductor, the faster the positive electrode conductor deteriorates. The positive electrode conductor is a critical element of a battery as it provides the means for electrical current to flow to and from the positive electrode. Thus, when the positive electrode conductor deteriorates, electrical current to and from the battery deteriorates. This deterioration causes the battery power to deteriorate, which in turn leads to battery failure.
Therefore, there is a need for extending the cycle life of a battery. More specifically, there is a need for extending the life of the positive electrode conductor to achieve extended cycle life of the battery.